Quantum Internet: The Future of Fast and Secure Internet Technology
What is the Classical internet?
Internet services are provided by various telecom companies throughout the world. In the USA, AT&T is a leading telecom company, whereas in Canada it is Rogers and India has Jio. Classical internet transmits data in bits of zeroes and ones. All information in the form of video, audio, pdf, word file, or any other format is converted into bits, and then the information is exchanged between a transmitter and a receiver. Over a period of 50 years, Classical internet has evolved and spread rapidly at a pace that was never anticipated in the initial days of the internet.
What is Quantum internet?
Quantum internet is a technology that researchers are working on to find new ways of transmitting information. Through Quantum internet, we will be able to transmit information in the form of quantum bits called qubits. Quantum internet will be built on the laws of quantum mechanics. Once deployed quantum internet will support distributed quantum applications, hardware heterogeneity, be flexible with regards to hardware heterogeneity, and ensure security at the network level.
Why do we need a Quantum internet when we already have a Classical internet?
Classical internet was invented 50 years ago. The inventors of the internet never imagined that it will be a part of our daily lives and we will depend on the internet to such a large extent. In recent years, users of the internet have also increased exponentially and there is a huge demand for the fastest and safest internet services. Currently, the world is using 4th generation Classical internet and we are all looking forward to the launch of the 5th generation. In this rapidly changing environment, constant internet traffic, the ever-increasing security concerns, and limitations of using classical internet has prompted researchers to work on the development of quantum internet as we need an advanced form of the internet which is more secure, dependable, advanced and fast.
What are the problems with the Classical internet?
Every day, the number of internet users is growing exponentially. In July 2020, there were 4.57 billion active internet users in the world. This accounts for 59% of the global population. The below graph represents the growth in the number of active internet users from 1995 to 2018
We started using the internet initially on our desktops. Today, we are using it on our mobile phones, laptops, TVs, smartwatches, smart speakers, and many more gadgets. Statistics show that there are 8 networked devices used per person and the number is expected to grow up to 13.6 devices per person by 2022.
This means that in the coming few years, the dependency on internet is going to increase rapidly. We need to keep working on new ways to tackle the ever-increasing threats of cybercrime.
Hackers, scammers, and cheaters are using the internet for online frauds, phishing scams by gaining access to personal information of internet users. There has been a sharp increase in cybercrimes as the number of internet users has increased all over the world.
How can Quantum internet outperform Classical internet?
Quantum internet is designed and built in such a way that it will fundamentally outreach Classical internet in terms of security, speed, and application. The information is transferred via qubits (quantum bits) which creates disturbed, entangled quantum states. One of the best features of the quantum internets is that you can access any quantum device securely.
Apart from the super-secure network connection it also provides quantum key distribution, clock synchronization, extending the baseline of the telescope, and many more applications will evolve as technology grows by leaps and bounds. To increase the computing potential, quantum processors can be linked with the quantum network to exchange the qubits between them. This process is called networked quantum computing or distributed quantum computing.
Quantum entanglement provides numerous advantages for quantum internet as it requires very small quantum processors. For instance, it can be one qubit because the process of entanglement requires just two qubits.
What are the stages to build Quantum internet?
There are three main essential hardware requirements to build quantum internet. These include the Quantum channel, quantum repeaters, and end nodes. Building the quantum internet which connects all the quantum processors with the quantum processor is a multi-stage process. Each step involves huge scientific research and engineering developments.
The important elements of the quantum network are:
1. End nodes (quantum processors)- End nodes are the quantum processors that are built to prepare and measure qubits and large-scale quantum computers. End nodes have an advantage that they can act as quantum repeaters and can have an in-built entanglement generator that can prepare EPR pairs. To transfer the signal, one of the nodes has to prepare and transmit information to any node for measurement in the qubit state. A network of the quantum network can also have non-quantum nodes that can handle classical network traffic. End nodes are in its predevelopment stage to work in quantum internet to its maximum potential. End nodes need to be robust, compatible, and provide high fidelity of quantum states.
2. Network stack — It consists of four layers on top of each other. At the bottom is the physical layer followed by the connectivity layer, link layer, and the top network layer. The physical layer corresponds to the quantum channels connecting the interacting quantum network devices. It can be a pre-existing optical fiber or free space network. This layer will send the qubit from one network device to the other without applying an error correction or distillation mechanism. The connectivity layer includes quantum repeaters, bi or multipartite for long-distance point to point and point to multi-point quantum communications. The link-layer defines the boundaries of a quantum network in terms of entangled, distributed, multipartite network state in which the networking devices of a quantum network share are in the static phase. The network layer is quantum routers which are responsible for generating and manipulating inter-network entanglement to enable graph state requests spanning several different quantum networks.
3. Quantum repeaters- A quantum repeater allows end to end generation of quantum entanglement and error correction. Currently, as the field is under research, error correction is only available for a short distance because for the long-distance, it would require many qubits with an extremely large quantum computer. Quantum repeaters allow entanglement and can be established at distant nodes without physically sending an entangled qubit for the entire distance.
What are the challenges and open problems in building Quantum internet?
Quantum internet is under development and researchers from all around the world are working on developing a quantum network system. The concerns in development include some major challenges like network functionalities, decoherence and fidelity, entanglement distribution, and deployment.
Quantum computer requires ultra-high vacuum and ultra-low temperature system for their functioning therefore individual researchers and students can access this facility via cloud system. It is expected that by 2024 half of the 10 billion will be the quantum cloud market. Current hardware and existing technological limits are a big barrier in the establishment of the quantum network of quantum processors for the quantum internet.
As the research in this field is making progress there have been exciting results coming from all over the globe, Prof. Stephanie Wehner from QuTech is working on Quantum internet and has the vision to connect three cities of the Netherlands via Quantum network and to test quantum internet in the coming 5-year plan. Researchers from China have successfully tested a Quantum network with a range of 2000 km through optical fiber connecting Beijing with Shanghai. It has been built for banking and commercial communications. Another event researcher from Pan lab has successfully teleported photons from ground-based stations to satellites 1400 km away. With an understanding of the importance of Quantum internet, the American government has unleashed a plan to build the prototype of an unhackable Quantum internet within 10 years in collaboration with the University of Chicago.
To summarize this, Quantum internet is still in the testing stage and highly skilled scientists and engineers are working on developing theory, experimenting, and building models of interdisciplinary research on quantum mechanics, computer science, and telecommunication engineering to make this happen.